I'll weigh in as well. I was a Paladin main in 2.0 and 2.1, and for 2.2 I've switched to Warrior as the other tank in my static wanted to continue maining Paladin, and I thought that 2 Paladins was a pretty outdated concept. Plus variation is always nice.
In terms of gameplay, you have a similar 123 aggro combo to Paladin. However that's where the similarities end. The Warrior 123 aggro combo is just an aggro combo and does nothing more out of that. You also have two more combos to Warrior - the Storm's Path (-10% damage debuff) combo, and the Storm's Eye (-10% slashing resistance) combo. When you have enough of an aggro lead, you can play around with the other 2 combos to increase your Maim uptime, and to provide some utility outside of spamming the aggro combo.
Overpower is a conal shape AoE aggro tool. It's superiority over Flash is that it does damage, and thus generates more aggro than Flash, however it consumes TP, and it's a conal shape AoE, compared to Flash being a circular AoE and using mana instead.
Once you get Warrior, managing your Wrath stacks are important, but for the most parts:
1. Steel Cyclone functions as a way better AoE aggro tool than Flash. It requires 5 stacks of Wrath to use, which is easy enough if you open your first pull with Infuriate, and try ending your group of trash mobs with 5 stacks of Wrath, so that you go into the next pull with 5 stacks up for an opening Steel Cyclone.
2. Inner Beast is your bread and butter tool against bosses. For most bosses you can use it to reduce all incoming damage by 20% for 5 seconds, however against certain bosses like Twintania, it allows you to almost always mitigate 20% damage off spike damage like Death Sentence. Call it something of a cooldown in demand.
In terms of offensive buffs, Berserk and Fight or Flight would be your 2 similar skills, however Berserk also applies a Pacification debuff on yourself at the end of its duration. When planning on how to use Berserk, just keep in mind if that 5 seconds of Pacification can be spared in battle. I usually chain Unchained and Berserk together for the biggest damage (and biggest opening aggro).
Warriors don't have as superior defensive cooldowns as Paladin, but Vengeance works as a huge long duration mitigation tool. I'd say the most important part of playing Warrior defensively is knowing when and how to use Holmgang as a pseudo-Hallowed Ground. Keep in mind that your HP cannot drop below 1 for its duration, but it has a shorter duration compared to Hallowed Ground, and both you and the target are rooted to the spot for the duration of Holmgang (unless the target resists rooting).